1. Field of the Invention
The present invention relates to a tightening and clamping device including a shaft, a first abutment supported on one end of the shaft, a second abutment supported on the shaft in a spaced relationship to the first abutment, an actuation member rotable about an axis of the shaft between a tightening and clamping position and a release position and operatively connected with the second abutment, the actuation member and the second abutment having adjacent surfaces, with an adjacent surface of one of the actuation member and the second abutment being provided with rolling tracks, and with rolling bodies being supported for a free rotation in another of the actuation member and the second abutment and being displaceable along the rolling tracks.
2. Description of the Prior Art
A tightening and clamping device of this type is disclosed, e.g., in a European Publication EP 0 600 700 BI. The rolling tracts, discussed in this publication, have three sections, namely, a first section along which a rolling body is displaceable in the unclamped position, a second section which represents a culminating point through which the rolling body must pass upon actuation of the actuation member, and a third section representing or forming the detent region in the clamped position of the device. The supporting surface of the detent region lies deeper than the culmination point and, as a result, during the transition from the unclamped position into the clamped position, the maximum achievable tension force, which is achieved at the culmination point, is again reduced when the rolling body moves into its detent position. Therefore, a portion of the tension force becomes lost.
European Publication EP 0 493 181 BI discloses a tightening and clamping device of the type discussed above in which a ball pair is used as the rolling bodies. The balls are located in the bores formed in the actuation member which pivots between two abutments. Upon pivoting of the actuation member, the rolling bodies, the balls, are displaced along rolling tracks formed as helicoidal surfaces. In the tightening and clamping position, the rolling bodies lie in recesses formed in the rolling tracks. Thus, the structure described in this publication has the same drawback which was discussed when describing the device disclosed in EP 0 600 700 BI.
An object of the present invention is to provide a tightening and clamping device of the type discussed above and in which the drawback characterizing the prior art devices is eliminated, and the maximum achievable magnitude of the tightening and clamping force is retained in the tightening and clamping position.